In many radio communication systems designed to service a large area, it is often desirable to provide a number of receivers, each positioned at a different location within the area to be serviced. Typically, the receivers, which may be base stations or repeaters, have overlapping effective reception ranges so that any messages transmitted within the area will be picked up by at least one receiver on the same frequency or channel. As an example of such a system, a communication unit transmits via a radio frequency (RF) communication resource a message that is received by three remote receivers. Each of the receivers sends its received signal to a comparator, also known as a voter, typically by wireline communications. The comparator receives and compares each message from each of the receivers and outputs a message that is comprised of either an entire message from one of the receivers or a composite message comprised of segments of the messages received from one or more of the receivers. Each message may be comprised of a plurality of message frames.
In RF communication systems, it is sometimes desirable to be able to transmit different messages consecutively from the same base station, in order to more effectively utilize the communication resources of the base station. Such transmissions, however, may be subject to interference caused by other base stations keying or dekeying on the same channel, particularly in the simulcast system.
Accordingly, there is a need for a method of voting that provides efficient use of communication resources, while avoiding interference caused by other signal sources, particularly in a simulcast system.